System and method for investigating large amounts of data

ABSTRACT

A data analysis system is proposed for providing fine-grained low latency access to high volume input data from possibly multiple heterogeneous input data sources. The input data is parsed, optionally transformed, indexed, and stored in a horizontally-scalable key-value data repository where it may be accessed using low latency searches. The input data may be compressed into blocks before being stored to minimize storage requirements. The results of searches present input data in its original form. The input data may include access logs, call data records (CDRs), e-mail messages, etc. The system allows a data analyst to efficiently identify information of interest in a very large dynamic data set up to multiple petabytes in size. Once information of interest has been identified, that subset of the large data set can be imported into a dedicated or specialized data analysis system for an additional in-depth investigation and contextual analysis.

BENEFIT CLAIM

This application claims the benefit under 35 U.S.C. §120 as aContinuation of application Ser. No. 13/167,680, filed Jun. 23, 2011,the entire contents of which are hereby incorporated by reference forall purposes as if fully set forth herein. Applicants expressly rescindany disclaimer of subject matter that may have occurred duringprosecution of the priority application and advise the USPTO that theclaims in the present application may be broader than the claims allowedin the priority application.

BACKGROUND

The present invention relates generally to computer-based data analysis.In particular, the present invention relates to computer systems andmethods for investigating and analyzing large amounts of data such as,for example, transaction logs of bank, call data records (CDRs),computer network access logs, e-mail messages of a corporation, or otherpotentially high-volume data that may contain up to billions totrillions of records.

Today, corporations, businesses, governmental agencies, and otherorganizations collect huge amounts of data, covering everything frome-mail messages, fined-grained web traffic logs to blogs, forums, andwikis. At the same time, organizations have discovered the risksassociated with the constantly-evolving cyber security threat. Theserisks take many forms, including exfiltration, cyber fraud, moneylaundering, and damage to reputations. In an attempt to reduce theserisks, organizations have invested in custom information technologyprojects costing hundreds of millions of dollars to manage and analyzecollected data. These projects typically involve the creation of a datawarehouse system for aggregating and analyzing the data.

Data warehousing systems have existed for a number of years, but currentdata warehousing systems are ill-suited for today's investigationchallenges for a number of reasons. These include:

1. Scale: inability to accommodate up to petabyte-scale data sets thatinclude up to billions or trillions of data records.

2. High-latency searches: search results to investigative queries shouldbe returned in a matter of seconds, not hours or days.

3. Data Silo-ing: lack of consolidation of an organization's relevantdata; instead, data collected by the organization is distributedthroughout multiple disparate database systems that are incapable ofreciprocal operation with one another; investigative searches forinformation require submitting a sub-search to each of the separatesystems and aggregating the search results, possibly in different dataformats, requiring development of time-consuming and expensive custominformation technology components.

4. Loss of original data: data cannot be accessed in its original form,instead transformed versions of the data are presented during analysispotentially causing loss of valuable context.

The present invention attempts to address these problems and others,facilitating low latency searches of very large and possibly dynamicdata sets in which search results present matching data in an originalform.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 illustrates an embodiment of the invention comprising a set ofinterconnected functional modules;

FIG. 2 illustrates an example operation of the parser of FIG. 1;

FIG. 3 illustrates an example operation of the transformer of FIG. 1;

FIG. 4 illustrates an example operation of the importer of FIG. 1;

FIG. 5 illustrates an example data model of the data repository of FIG.1;

FIG. 6 illustrates yet another example data mode of the data repositoryof FIG. 1;

FIG. 7 illustrates yet another example data model of the data repositoryof FIG. 1

FIG. 8 is a flowchart illustrating logic for performing an examplesearch using the system of FIG. 1;

FIG. 9 is a flowchart illustrating logic for performing another examplesearch using the system of FIG. 1;

FIG. 10 is a block diagram of a computer system in which an embodimentof the invention may be implemented;

DETAILED DESCRIPTION OF PERFERRED EMBODIMENT(S)

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. It will be apparent, however,that the present invention may be practiced without these specificdetails. In other instances, well-known structures and devices are shownin block diagram form in order to avoid unnecessarily obscuring thepresent invention.

Several embodiments are described hereafter that can each be usedindependently of one another or with any combination of the otherembodiments. However, any individual embodiment might not address any ofthe problems discussed above or might only address one of the problemsdiscussed above. Some of the problems discussed above might not be fullyaddressed by any of the embodiments described herein. Although headingsare provided, information related to a particular heading, but not foundin the section having that heading, may also be found elsewhere in thespecification.

Example embodiments will be described according to the followingoutline:

1.0 Functional Overview

2.0 Structural Overview

-   -   2.1 Data Sources    -   2.2 Distributed Key-Value Data Repository    -   2.3 Exemplary Data Repository Data Model    -   2.4 Adaptors        -   2.4.1 Parser        -   2.4.2 Transformer        -   2.4.3 Importer

3.0 Example Search Operation

-   -   3.1 Example Single-Level Search    -   3.2 Example Two-Level Search

4.0 Example Implementing Mechanism

1.0 Functional Overview

According to some embodiments, the present invention aims to provide newand useful system implementing methods for investigating large amountsof data. The system is massively scalable, may operate on commodityhardware, and solves the problem of silo-ing of large-scale databasesthough the system's capability of ingesting data from disparateheterogeneous data sources in a single data repository that providesindexing and efficient searching of ingested data. The system isflexible in that it is agnostic with respect to data formats. The systemis adaptive in that it facilitates data analyst-driven queries on anextremely large volume of data that is constantly being updated.

In general terms, the system uses a horizontally-scalable distributedkey-value data repository to index data obtained from potentiallymultiple disparate data sources. Examples of data include, but are notlimited to, network traffic and access logs, bank transaction records,call data records, e-mail messages, netflows, electronic blogs, forums,wikis, etc. More generally, data includes, but is not limited to, anycharacter data that reflects an activity of an individual person ororganization. The activity may be an online activity such as, forexample, accessing a website, sending or receiving an e-mail, or makingan online payment with a credit card or an offline activity such as, forexample, using a key card to gain access to a building. Typically, butnot always, data includes timestamps indicating when the activities tookplace.

The indexing process includes parsing the data to derive index keys fromparse tokens, either using parse tokens as index keys or transformingparse tokens to use as index keys, or a combination of the two. At thesame time, the process divides the data into relatively small datablocks, which may be compressed, and stored in the data repository keyedby an assigned identifier.

In some embodiments, the system supports at least two types of searches:single-level and two-level. Each of the two types has a correspondingindexing scheme. For both single-level searches and two-level searches,the data repository holds a “key-value family” mapping data blockidentifiers to blocks of data. As used herein, the term “key-valuefamily” refers generally to an identifiable set of related key-valuepairs in which keys are mapped to values. Within a key-value family,keys may be unique. A key may be mapped to more than one value anddifferent keys may be mapped to different numbers of values. Both thekeys and the values may an arbitrary byte sequences representing astring, a number, or binary data, for example.

In some embodiments, in a single-level search, a first key-value familymaps keys derived from parse tokens to data block identifiers and asecond key-value family maps data block identifiers to data blocks. Toconduct a single-level search specifying search criterion, the systemdetermines a set of one or more data block identifiers from the firstkey-value family that are keyed by a key that matches the searchcriterion. The determined set of data block identifiers are then used todetermine a set of one or more data blocks from the second key-valuefamily using the determined set of data block identifiers as keys to thesecond key-value family.

In some embodiments, a data block identifier in the first key-valuefamily is supplemented with snippet identifying information identifyinga byte sequential portion of the identified data block. The snippetidentifying information may a byte offset and a byte length, forexample. Alternatively, the snippet identifying information may be, forexample, line number information identifying line(s) of the identifieddata block. The system may return search results by (i) uncompressingthe determined set of data blocks, if compressed; (ii) using thesupplemental information to identify snippets in the uncompressed datablocks, and (iii) returning the identified snippets as search results.An example of a single level search is “all e-mail messages sent from orreceived by [X]” where [X] is the search-specified first criterion andmay be an e-mail address or a person's name, for example.

In some embodiments, for a two-level search, an additional key-valuefamily is used. A first key-value family maps keys to keys of a secondkey-value family. In other words, values of the first key-value familyare keys of the second key-value family. The second key-value family inturn maps values of the first key-value family to data blockidentifiers; a third key-value family maps data block identifiers todata blocks.

In some embodiments, to conduct a two-level search specifying a firstcriterion and one or more second criteria, the system determines a setof one or more values from the first key-value family that are keyed bya key that matches the first criterion and that satisfy the secondcriteria. In other words, only values of that key that satisfy thesecond criteria are included in the set. The system then determines aset of data block identifiers from the second key-value family that arekeyed by keys that match the set of values determined from the firstkey-value family. The determined set of data block identifiers are thenused to determine a set of data blocks from the third key-value family.In some embodiments, a data block identifier in the second key-valuefamily is supplemented with snippet identifying information. An exampleof a two-level search is “all e-mail messages sent by [X] in the past[Y] days” where [X] is the first criterion and [Y] is the secondcriteria.

In some embodiments, the keys are byte sequences derived from selectedparse tokens of the input data. The parse tokens that are selected mayvary depending on the type of data and the type of queries expected tobe performed. For example, keys for e-mail messages may include senderand/or recipient e-mail addresses. As another example, keys for webaccesses logs may include internet protocol (IP) address, uniformresource locators (URLs), etc.

In some embodiments, snippets of uncompressed data blocks are returnedas results to searches thereby providing the data in its original formin the search results. For example, the results to the above examplesearches may return the contents of the actual e-mail messages.

In some embodiments, the system of the present invention enablesorganizations to leverage their existing investments in traditionalcomputer-based data analysis systems which may be designed for specificinvestigative tasks or suited for specific types of data. Moreparticularly, once information of interest has been uncovered by asearch using the system of the present invention, that subset of thedata can be incorporated into another data analysis system foradditional in-depth investigation and contextual analysis. In effect,the system of the present invention can be used to filter a very largeset of data to identify only that subset of the cyber set that requiresfurther investigation and analysis without over-burdening orover-populating traditional, dedicated, or other data analysis systemswith large amounts of data “noise”.

With regard to scalability, the system of the present invention mayscale horizontally across commodity hardware to handle up to hundreds ofterabytes to petabytes of data. The system may store the data in acompressed form for storage space efficiency and without needing to keepindexes in volatile memory. The system may be fault tolerant throughreplication across nodes and data centers and can be scaled withoutdowntime.

In some embodiments, the system utilizes a distributed, “NoSQL” datarepository to hold both the data and selective indexes. The data may becompressed into data blocks before being written to disk. Highthroughput import of data may be accomplished with in-memory writebuffering and bulk serialization to disk. The system can provide lowlatency searches by its ability to scale horizontally across a number ofcomputing nodes. In some embodiments, any node may be used to processsearches.

Further, the indexing and searching solution of the present inventioncan operate where the data repository supports a limited set of queryoperations. In particular, the solution can operate where only equalityand range query operations on keys and values are supported. Notably,the solution can effectively operate where wildcard operators, “like”operators, or regular-expression-based pattern matching query operatorsare not supported by the data repository.

In some embodiments, the system is agnostic to data format and caningest virtually any type of structured data: from call data records(CDRs) to netflows to virtually any other data or file format.

Typical applications of the current invention include the investigationand analysis of extremely large amounts (e.g., hundreds of terabytes) ofdata of multiple heterogeneous data sources such as log files, e-mailmessage spools, transaction logs, call data records, etc. that might befound in a business, organization, governmental agency, school,university, hospital, etc. With the system of the present invention, adata analyst can investigate top-down trends, behaviors, and activitiesor bottom-up target centric analysis across a larger dataset.

The invention which includes both method and apparatus aspects (i.e.,apparatus comprising respective means to perform the steps of themethods), may be embodied within various kinds of hardware including oneor more general purpose computers such as the general purpose computer1000 of FIG. 10.

2.0 Structural Overview

2.1 Data Sources

FIG. 1 shows the overall structure of an embodiment of the invention.Referring to FIG. 1, an organization may manage one or more data sources101 that generate data, perhaps continuously or on an ongoing orperiodic basis. Any sizeable organization typically will manage multipledata sources 101 that generate vast amounts of data. Example datasources 101 include databases, log files, transaction logs, call datarecords, access logs, netflows, authentication logs, authorization logs,e-mail message spools, and any other data container for data.

Data generated by data sources 101 includes, but is not limited to, anycharacter data that reflects an activity of an individual person ororganization. The activity may be an online activity such as, forexample, accessing a website, sending or receiving an e-mail, or makingan online payment with a credit card or an offline activity such as, forexample, using a key card to gain access to a building. Typically, butnot always, data includes timestamps indicating when the activities tookplace.

Typically, but not always, data generated by data sources 101 adheres tosome sort of data structure or data format. For example, data stored ina database may adhere to a relational database structure or relatedschema. As another example, data in a log file may be formatted ineXtensible Markup Language (XML) or similar markup language. As yetanother example, data may be formatted in plain-text (e.g., ASCII) withwhitespace characters (e.g., tab, space, and newline characters)providing structure. Other data formats are possible and anymachine-parse-able character-based data format is contemplated as beingwithin the scope of the invention.

Data sources 101 of an organization may generate and collect extremelylarge amounts of data. Organizations would appreciate a way toefficiently sift through this data to quickly identify information ofinterest or information pertinent to a line of inquiry. The informationof interest may be as fine-grained or finer-grained as, for example, asingle e-mail message amongst hundreds of thousands or even millions ofe-mail messages stored across multiple e-mail servers. The informationof interest may not be known a priori. In other words, organizations maywish to pursue an investigative line of inquiry in which the data isiteratively searched until information of interest is revealed ordiscovered. In this case, searches of data that take hours or days tocomplete or that require submission of search queries to multiple dataanalysis systems would be inefficient. In one respect, organizationswould appreciate a single tool that allows them to quickly find ordiscover the proverbial “needle in the haystack” in which a 100 bytesnippet of a single web access log file, for example, is analogous tothe needle and petabytes of data collected by hundreds of differentheterogeneous data sources, for example, is analogous to the haystack.

To address the need to efficiently investigate and analyze large amountsof data, the system of FIG. 1 is proposed. The system includes adistributed key-value data repository 111, one or more adaptors 103, anda search mechanism 113 with a search interface 114. The data repository111, the adaptor(s) 103, the search mechanism 113, and the searchinterface 114 may be interconnected to one another using any suitabledata communication mechanism such as, for example, one or more datanetworks. The one or more data networks may include one or more localarea networks (LANs), one or more wide area networks (WANs), or theInternet. The components of the system may be distributed across one ormore computer systems such as the computer system 1000 of FIG. 10.Alternatively, some or all components may be embodied within a singlecomputer system. When distributed across multiple computer systems,components may additionally be distributed geographically, for example,across one or more data centers.

2.2 Distributed Key-Value Data Repository

The distributed key-value data repository 111 may operate on a clusterof computing nodes 112. The nodes 112 of the cluster may beinterconnected via a communication bus such as one or more local areadata networks, one or more wide area data networks, the Internet, orother suitable data network or communication mechanism. In oneembodiment, a node 112 is a server computer system comprised ofcommodity or readily-available hardware components running a serveroperating system such as a Microsoft Windows®-based, Unix-based, orLinux-based operating system for example. A node 112 may also beimplemented by a virtual machine system or other software-basedimplementation of a computing device.

Very generally, data is stored in the data repository 111 as key-valuepairs. The number of key-value pairs can amount to a very large data setup to hundreds of terabytes to even petabytes of data. To handle suchsize, the data repository 111 allows key-value pairs to be distributedacross the nodes 112 of the cluster.

The data repository 111 may be decentralized. In some embodiments, everynode 112 in the cluster performs the same function or functions.Key-value pairs may be distributed across nodes 112 of the clusteraccording to a key distribution scheme. Each key may have one or moremaster nodes 112 to which the key is assigned according to the keydistribution scheme. Each node 112 may have partitioner logic thatexecutes on the node 112 for carrying out the key distribution scheme.The partitioner logic of each node 112 of the cluster may distributekeys randomly across the nodes 112 using a consistent hashing technique,for example. Other key distribution schemes may be used by the nodes 112and the present invention is not limited to any particular keydistribution scheme.

In some embodiments, any node 112 in the cluster can receive and servicea read or write request for any key, even if the requested key ismastered by other node(s) 112 in the cluster. To do so, the partitionerlogic at the receiving node 112 determines, based on the requested key,which node(s) 112 in the cluster are the master node(s) 112 for therequested key and sends the request to one or more of the master node(s)112. In the case where the node 112 receiving a request for a given keyis not a master node 112 for that key, the node 112 receiving therequest effectively acts a “proxy” node 112 for the key.

The data repository 111 may be elastic. A new node 112 can be added tothe cluster without causing downtime to the existing nodes 112 in thecluster. As new nodes 112 are added, data repository access (reads andwrites) throughput may be increased. New keys may be distributed acrossthe new nodes 112.

The data repository 111 may be fault-tolerant. Key-value pairs can bereplicated across multiple nodes 112 in the cluster so that for a givenkey, multiple nodes 112 are master nodes 112 for that key. Thus, thedata repository 111 can prevent single points of failure. The datarepository 111 or nodes 112 thereof may be replicated across multipledata centers or different geographical locations.

The data repository 111 may be eventually consistent (as opposed tostrictly consistent) so that access (reads and writes) latency is keptto a minimum and so that the data repository 111 has a high availabilityin the event of node 112 failures. Thus, the data repository 111 neednot be an (Atomic, Consistent, Isolated and Durable) ACID-compliant datastore.

The data repository 111 may support a limited set of query operations onkeys and values. In particular, the data repository 111 may support onlyequality (e.g., “=”) and range operations (e.g., “>=”, “>”, “<”, and“<=”) on keys and values. In some embodiments, searches are conducted onthe data repository 111 using equality operators on keys and usingequality and/or range operators on values.

The data repository 111 may provide high throughput import of data within-memory write buffering and bulk serialization to non-volatilestorage. As mentioned, a write of a key-value pair to the datarepository 111 may be made at any node 112 in the cluster. For faulttolerance, the node 112 receiving the write may record the key-valuepair to a local append-only commit log stored in a non-volatile memoryof the receiving node 112. As an append-only log, this recordation is afast operation requiring no disk seeking. The partitioner logic of thereceiving node 112 then uses the key to determine the master node(s) 112for the key. If the receiving node 112 is not a master node 112 for thekey or not the only master node 112 for the key, then the receiving node112 sends the write to the other master node(s) 112 for the key. Eachnode 112 in the cluster maintains a volatile memory table for collectingbatches of key-value pair writes for which the node 112 is a master.Each node 112 periodically flushes its volatile-memory table to anon-volatile memory of the node 112 where the key-value pairs arepermanently stored. The volatile memory table may be flushed to anon-volatile memory when the table is full, there are threshold numberof key-value pairs in the table, on a set time interval, for example.

In some embodiments, the data repository 111 is implemented using theApache Cassandra distributed database management system. ApacheCassandra is open source software maintained by the Apache SoftwareFoundation and currently available online at the Internet domaincassandra.apache.org. In other embodiments, the data repository 111 isimplemented using the Apache HBase distributed database managementsystem. Apache HBase is open source software maintained by the ApacheSoftware Foundation and current available online at the Internet domainhbase.apache.org. However, other distributed key-value data storesystems may be used for the data repository 111 and the presentinvention is not limited to only the Apache Cassandra system or theApache HBase system.

2.3 Exemplary Data Repository Data Model

Turning now to FIG. 5, therein is shown a block diagram of an exemplarydata model 500 for the data repository 111 of FIG. 1. Very generally,the data model 500 contains one or more keyspaces 501 which in turn eachcontain one or more key-value families 502. A keyspace 501 is a namedcollection of related key-value families 502. The data repository 501may contain multiple keyspaces 501. Each keyspace 501 may contain one ormore key-value families 502.

A key-value family 502 is named set of related key-vale pairs. Key andvalues are variable length byte sequences. In many cases, the bytesequence of a key represents a character string such as, for example, ane-mail address. The string may be encoded according to a characterencoding scheme (e.g., UTF-8). In many cases, the byte sequence of avalue also represents a character string. In other cases, the bytesequence of a value represents raw binary data. The byte sequence of akey or value can also represent other data types such a numbers,date/times, etc.

Keys of a key-value family 502 may be unique. A key may map to more thanone value and different keys may map to different numbers of values. Forexample, in the key-value family 502 of FIG. 5, “key1” maps to twovalues while “key2” maps to only one. The values of a key may be storedor arranged by the data repository 111 in a sorted order based on thevalues of the key.

Depending on the key distribution scheme employed by the data repository111, keys of a key-value family 502 may be distributed across a numberof nodes 112 of the data repository 111 cluster. Some keys of akey-value family 502 may be mastered on one node 112 while other keys ofthe key-value family 502 may be mastered on another node 112. More nodes112 may be added to the cluster as the size (e.g., the number of keys)in a key-value family 502 grows. New keys added to the key-value family502 may be mastered by the new nodes 112. A single key-value family 502may contain up to billions of key-value pairs amounting to terabytes oreven petabytes of data. In one embodiment, all values for a given keyare mastered on the same node 112 that the given key is mastered. Thus,for a given key, one node 112 may master all of the values to which thekey maps.

2.4 Adaptors

The adaptor(s) 103 are the mechanism by which input data 102 is ingestedinto the system and stored in the data repository 111. There may be anadaptor 103 for each type of data source 101. For example, the may be anadaptor 103 for ingesting input data 102 produced by a database systemdata source 101 and another adaptor 103 for a web access log data source101. There may be separate adaptors 103 for separate instances of thesame type of data source 103. For example, there may be one adaptor 103for an instance of an e-mail server data source 101 in the Los Angelesoffice and another adaptor 103 for and another instance of an e-mailserver data source 101 in the New York office. A single adaptor 103 mayingest input data 102 produced by multiple types or multiple instancesof data sources 101. For example, a single adaptor 103 may ingest inputdata 102 produced by multiple database server data sources 101 or adatabase server data source 101 and a network access log data source101. Thus, a one-to-one correspondence between adaptors 103 and datasources 101 is not required and one-to-many, many-to-one, ormany-to-many configurations are possible across different types anddifferent instances of data sources 101.

In this document the term “input data” is used to mean data that ispresented as input to the system. That is, data that is obtained by anadaptor 103 from a data source 101 for processing and possible ingestinto the data repository 111.

An adaptor 103 may obtain input data 102 through any number of meansincluding receiving input data 102 from a data source 101 or retrievinginput data 102 from a data source 101. If receiving, the adaptor 103may, for example, receive the input data 102 in one or more networkmessages or event notifications. In this case, the adaptor 102 may havea network listener to which the data source 101 can connect and providethe network message or event notification. If retrieving, the adaptor103 may, for example, periodically access or connect to a data source101 to obtain input data 102 as a network client of the data source 101.Other techniques for obtaining input data 102 may be used according tothe requirements of the implementation at hand. The present invention isnot limited to any particular technique by which an adaptor 103 obtainsinput data 102.

However obtained, an adaptor 103 processes a stream of input data 102 aspart of a data processing pipeline of the adaptor 103. The input to thedata processing pipeline includes the stream of input data 102 obtainedfrom one or more data sources 101. The output includes a stream ofcompressed or uncompressed blocks 105 of data 102 and a stream ofkey-value pairs 110 to be stored in the data repository 111.

In some embodiments, the data processing pipeline includes a parser 104,a transformer 107, and an importer 109. The parser produces the streamof data blocks 105 and a stream of parse tokens 106. The transformer 107produces a stream of transformed parse tokens 108 from the stream ofparse tokens 106 produced by the parser 104. The importer 109 producesthe stream of key-value pairs 110 from the stream of transformed parsetokens 108 produced by the transformer 107.

The stream of input data 102 processed by an adaptor 103 may be obtainedcontinuously or essentially continuously by the adaptor 103 as datasources 101 generate new data. For example, an adaptor 103 for a webaccess log file may obtain input data 102 as a web server process iswriting to the log file. In this case where the stream of input data 102is continuous or essentially continuous, the data repository 111 is alsocontinuously or essentially continuously updated with new data blocks105 and new key-value pairs 110. Old or stale data can be purged fromthe data repository 111 to effectively provide a rolling window of anorganization's data. Alternatively, an adaptor 103 may be configured toobtain a fixed amount of data to create a snapshot of the organization'sdata in the repository 111. A combination of continuous/essentiallycontinuous and fixed amount may be used as well. For example, someadaptors 103 may be configured to obtain input data 102 from datasources 101 continuously or essentially continuously while otheradaptors 103 may be configured to obtain a set amount of input cyber 102from other data sources 101.

As mentioned, in one embodiment, the data processing pipeline of anadaptor 103 includes a parser 104, a transformer 107, and an importer109. It will be understood that these and other associated buildingblocks and components of an adaptor 103, may be configured asstand-alone logic elements, or may be combined together in one or moreassemblies, as needed or appropriate for the particular implementationat hand. A logic element may be implemented in software, hardware, orcombination of hardware and software.

2.4.1 Parser

One responsibility of the parser 104 is to divide the stream of inputdata 102 into discrete data blocks 105. The data blocks 105 are storedin the data repository 111 and indexed by the key-value pairs 110 storedin the data repository by the importer 109. How the parser 104determines to divide the stream of input data 102 into data blocks 105may vary depending on the type of the input data 102. A number ofdifferent strategies may be employed by the parser 104 to divide theinput data 102 stream into data blocks 105. These strategies include,but are not limited to:

“logical data entity”. In this strategy, the parser 104 divides theinput data 102 stream along identifiable logical data entity boundariesin the stream. A data block 105 is produced for each logical data entityin the stream. This strategy can be effective when the logical dataentities are of a sufficient byte size. What is a sufficient byte sizemay vary depending on the optimal byte size range for storage of valuesin the key-value repository 111. For example, if the input data 102stream is a stream of e-mail messages, then the parser 104 may produce adata block 105 for each e-mail message.

“byte count”. In this strategy, the parser 104 divides the input data102 stream into uniform or essentially uniformly sized data blocks 105.This strategy may be effective when the logical data entities in thestream are relatively small. In this case, multiple logical dataentities can be captured by the parser 104 in a single data block 105.For example, if the input data 102 stream is from a web access log filedata source 101, each logical data entity of the log file (i.e., eachweb access log entry) may consist only of a few lines of text data. Inthis case, it may be more efficient for the parser 104 to bundle manylogical data entities from the input data 102 stream in a single datablock 105.

“combination”. The strategy involves a combination of the “logical dataentity” strategy and the “byte count” strategy. In particular, theparser 104 determines the size of each logical data entity in the inputdata 102 stream. If the size exceeds a size threshold, then a data block105 is produced for the logical data entity. If the size is less thanthe threshold, then the parser 104 collects a number of successivelogical data entities from the stream until the threshold is exceeded atwhich point the parser 104 produces the collected logical data entitiesas a single data block 105.

Another responsibility of the parser 104 is to parse logical dataentities in the input data 102 stream to produce parse tokens 106.Similar to how the parser 104 determines to divide the input data 102stream into data blocks 105, what parse tokens 106 are produced by theparser 104 from a logical data entity may vary depending on the type ofthe input data 102. Further, the parse tokens 106 produced may varydepending on the expected lines of inquiry to be pursued with thesystem. For example, one line of inquiry might be to identify e-mailmessages sent by person X in the past Z days. Another example line ofinquiry might be to identify all systems that were accessed from a giveninternet protocol (IP) address. In the first example, each logical dataentity may correspond to an e-mail message and the parser 104 may parseeach e-mail message for the e-mail address of the sender and the e-mailaddress(es) of the recipient(s). The sender's and recipients' e-mailaddresses may be produced by the parser 104 as parse tokens 106. In thesecond example, each logical data entity may correspond to an entry in asystem access log and the parser 104 may parse the entry for the IPaddress of the accessing network peer logged in the entry.

Responsibilities and functions of the parser 104 of FIG. 1 will now beexplained in greater detail with reference to FIG. 2. As shown, theparser obtains a stream of input data 102. The stream includes a seriesof logical data entities 201 with perhaps some breaks or gaps 202 in thestream between successive logical data entities 201. Depending on thedata format of the input data 102, the parser 104 parses the input data102 to identify the boundaries of logical data entities 201 in thestream. Generally, this involves identifying defined or known bytesequences in the input data 102 that indicate the boundaries. The bytesequences may be identified through a syntactical analysis of thestream. For example, if the input data 102 is from an access log file,then the byte sequences may correspond to a newline character or anewline character and carriage return character sequence. The parser 104may use third-party Application Program Interfaces (APIs) or third-partysoftware libraries to parse input data 102 and identify the logical dataentities 201 therein. Break or gap data 202 may be discarded by theparser 104.

As the parser 104 identifies logical data entities 201 in the input data102, the parser 104 groups them into data block items 203. The parser104 sends a stream of data block items 203 to the data repository 111for storage, for example, by issuing and sending database commands tothe data repository 111. Each data block item 203 may include akey-value family identifier 204, a data block identifier 205, and a datablock 105. The format and type of the logical data entities 201 of adata block 105 may vary depending on the type of the input data 102. Forexample, a logical data entity 201 may be an e-mail message, a log fileentry, a call data record, a netflow record, or any other logical dataentity of data.

The key-value family identifier 204 identifies the key-value family 502in the data repository 111 in which the data block identifier 205 andthe data block 105 of the data block item 203 is to be stored as akey-value pair. The data block identifier 205 is the key and the datablock 105 is the value of the key-value pair. Although not shown, thedata block item 203 may also include a keyspace identifier to identifythe keyspace 501 that contains the key-value family 502 identified bythe key-value family identifier 204. Alternatively, the parser 104 mayhave specified a keyspace 501 to the data repository 111 in a previouscommunication with the data repository 111 such as, for example, whenestablishing a networking session with the data repository 111.

The data block identifier 205 is used to identify the associated datablock 105 in the data repository 111. The data block identifier 205 maybe any byte sequence suitable for uniquely identifying the associateddata block 105 within the data repository 111, or within a keyspace 501as the case may be. For example, the data block identifier 205 may be auniversally unique identifier (UUID) or generated by applying a MDS,SHA, or similar cryptographic hash algorithm to the associated datablock 105. Other types of identifiers may be used and the presentinvention is not limited to any particular type of data blockidentifier.

The data block 105 of a data block item 203 may be compressed by theparser 104. Any suitable lossless data compression algorithm may be usedfor this purpose (e.g., GNU Zip). Alternatively, the parser 104 may senddata blocks 105 to the data repository 111 uncompressed where they arecompressed by the data repository 111, effectively delegatingcompression of the data blocks 105 to the data repository 111. In eithercase, data blocks 105 are preferably stored in the data repository 111in a compressed form for efficient use of data repository 111non-volatile memory storage space. However, data blocks 105 may bestored in the data repository 111 in an uncompressed form if desired.

The parser 104 also produces a stream of parse items 206 from the inputdata 102. The parser 104 provides the stream of parse items 206 to thetransformer 107. The parser 104 may produce a parse item 206 for one ormore logical data entities 201 in the input data 102 stream. Thus, aparse item 206 may be associated with one or more corresponding logicaldata entities 201 from the input data 102 stream.

As shown, a parse item 206 may include, among other information, a datablock identifier 205 and one or more parse tokens 106. The parser 104may have extracted the one or more parse tokens 106 from the one or morelogical data entities 201 corresponding to the parse item 206. The datablock identifier 205 may identify the data block 105 containing the oneor more corresponding logical data entities 201. The parser 104 maygenerate one or more parse items 206 for the same data block 105.

In some embodiments, a parse item 206 additionally specifies snippetidentifying information 207. For example, the snippet identifyinginformation 207 may be a byte offset into an uncompressed data block 105and a byte length. The byte offset and the byte length may identify asnippet (byte sequential portion) of the uncompressed data block 105.For example, the byte offset may be a numerical value identifying anumber of bytes from a beginning of the uncompressed data block 105. Thenext byte length number of bytes of the uncompressed data block 105constitutes the snippet. As another example, the snippet identifyinginformation 207 may identify a line number or line number(s) of theuncompressed data block 105 that constitute the snippet. The snippet maybe all of, some of, or a portion of the one or more logical dataentities 201 corresponding to the parse item 206. Other information in aparse token item 206 may include a keyspace 501 identifier.

Parse tokens 106 identified in the input data 102 are selected bytesequences of the input data 102 identified by the parser 104. Which bytesequences are selected may vary depending on the type of logical dataentities 201 of the input data 102 and/or the expected searches to beconducted on the input data 102 using the system. For example, for aSimple Mail Transport Protocol (SMTP)-based e-mail message, the parsetokens 106 may include the header values from the SMTP header of thee-mail message (e.g., the “Received:”, “Date:”, “To:”, “From:”,“Sender:”, and “Subject:” headers). If, for example, the system will beused to search on e-mail subject, then the value of the “Subject:”header may be further tokenized by the parser 104 to separate each wordof the subject into individual parse tokens 106. Alternatively, theentire subject of the e-mail message may be treated as a single parsetoken 106. Other parse tokens 206 may be selected for e-mail messages orfor different types of input data 102.

2.4.2 Transformer

An adaptor 103 may include a transformer 107 for optionally transformingparse tokens 106 produced by the parser 104. Such transforming mayinclude, but is not limited to:

“Canonicalization”. Parse tokens 106 representing values that havemultiple possible representations may be transformed into a standardizedor normalized format. For example, string values may be converted to alllowercase characters. As another example, time and date values may beconverted into a string representing a numerical value representing anumber of time units (e.g., milliseconds) since an epoch.

“Concatenation”. One parse token 106 may be appended to another parsetoken 106 to produce yet another concatenated parse token. Whenappending parse tokens 106 together to form a concatenated parse token,delimiters (e.g., whitespace characters or other special byte sequences)may be introduced so that the individual constituent parse tokens 106are identifiable in the concatenated parse token.

“Truncation”. The beginning or end portion of parse token 106 may beremoved.

“Lookup”. A parse token 106 may be replaced with or concatenated withanother byte sequence retrieved from a data dictionary, an externaldatabase, etc. using the original parse token 106 as a key to the datadictionary, external database, etc. The original parse token 106 isprovided by the transformer 107 to the data dictionary, externaldatabase, etc. and in return receives a byte sequence to use in place ofthe original parse token 106 or to concatenate with the original parsetoken 106.

“Conversion”. A parse token 106 may be converted from one data format toanother. For example, a non-ASCII string may be converted to UTF-8.

The above are just examples of some of the types of the transformationsthe transformer 107 may perform on parse tokens 106. Other types oftransformation are possible and the transformer 107 is not limited toonly those transformations discussed above.

FIG. 3 illustrates an example operation of the transformer 107 ofFIG. 1. As shown, the transformer 107 obtains a stream of parse items206 from the parser 104. From the input stream of parse items 206 thetransformer 107 produces an output stream of parse items 206 whichincludes zero or more transformed parse tokens 108. In particular, eachoutput parse item 206 corresponds to an input parse item 106 in whichnone, some, or all of the parse tokens 106 of the input parse data item206 have been transformed by the transformer 107. Thus, an output parseitem 206 may contain the same, fewer, or more parse tokens than itscorresponding input parse item 206 may include one or more parse tokens106 received from the parser 104 that the transformer 107 did nottransform. In the example shown in FIG. 3, one output parse item 206contains at least one transformed parse token 108.

2.4.3 Importer

One responsibility of the importer 109 is to store the parse tokens 106and/or transformed parse tokens 108 in the data repository 111 in amanner that indexes the data blocks 105. As will be explained in greaterdetail below, a data analyst may then conduct a search on the indexes tofind snippets of data blocks 105 of interest. How the importer 109organizes the indexes typically will be dictated by the expectedsearches to be conducted using the indexes. As mentioned previously, insome embodiments, at least two types of searches are supported by thesystem of the present invention: single-level searches and two-levelsearches. Each type of search may have a corresponding data model in thedata repository 111 that supports it. Before describing an exampleoperation of the importer 109, exemplary data models supportingsingle-level searches and two-level searches will be described.

Single-Level Search:

Referring now to FIG. 6, according to some embodiments, in the datamodel 600 supporting a single-level search, a first key-value family602A maps keys derived from parse tokens 106/108 to data blockidentifiers 205 and a second key-value family 602B maps the data blockidentifiers 205 to data blocks 105.

In some embodiments, to conduct a single-level search specifying searchcriterion using this data model 600, the search mechanism 113 determinesa set of one or more data block identifiers 205 from the first key-valuefamily 602A that are keyed by a key that matches the search criterion.The determined set of data block identifiers 205 are then used todetermine a set of one or more data blocks 105 from the second key-valuefamily 602B using the determined set of data block identifiers 205 askeys to the second key-value family 502.

In some embodiments, a data block identifier 205 in the first key-valuefamily 602A may be supplemented with snippet identifying information 207identifying a snippet of the identified data block 105. The searchmechanism 113 may then return search results by (i) uncompressing thedetermined set of data blocks 105, if compressed; (ii) using thesupplemental snippet identifying information 207 to identify snippets inthe uncompressed data blocks 105, and (iii) returning the identifiedsnippets as search results.

In some embodiments, a first key-value family 602A contains key-valuepairs 110 produced by one or more adaptor(s) 103. Recall that a key of akey-value family can have more than one value. In the data model 600,each value of a key of the first key-value family 602A may “point” 601to a data block 105 from which the key was derived by an adaptor 103. Asan example, if the keys of the first key-value family 602A are sendere-mail addresses obtained from a set of e-mail messages, then a key inthe first key-value family 602A may map to multiple values, one value,for example, for each e-mail message of the set of e-mail messages sentfrom a particular e-mail address. Each value in the first key-valuefamily 602A in this case for example may point 601 to a data block 105containing the corresponding e-mail message.

In some embodiments, the value of a key-value pair 110 in the firstkey-value family 602A is a composite value comprising a data blockidentifier 205 and snippet identifying information 207 identifying asnippet of the uncompressed data block 105 identified by the data blockidentifier 205. In some embodiments, this snippet is returned as asearch result. For example, the snippet may be an e-mail message, a logentry, a call data record (CDR), or other logical data entity of data.

In some embodiments, the second key-value family 602B contains datablocks 105 produced one or more adaptor(s) 103. Keys of the secondkey-value family 602B may be data block identifiers 205. Values of thesecond key-value family 602B may be data blocks 105, either compressedor uncompressed. In some embodiments, each key in the second key-valuefamily 602B maps to only one data block 105.

Two-Level Search:

Referring now to FIG. 7, according to some embodiments, in the datamodel 700 supporting a two-level search, an additional key-value familyis used. A first key-value family 702A maps keys to keys of a secondkey-value family 702B. In other words, values of the first key-valuefamily 702A are keys of the second key-value family 702B. The secondkey-value family 70B in turn maps values of the first key-value family702A to data block identifiers 205. A third key-value family 702C mapsdata block identifiers 205 to data blocks 105.

According to some embodiments, to conduct a two-level search specifyinga first criterion and one or more second criteria using this data model700, the search mechanism 113 determines a set of one or more valuesfrom the first key-value family 702A that are keyed by a key thatmatches the first criterion and that satisfy the second criteria. Inother words, only values of that key that satisfy the second criteriaare included in the set. The search mechanism 113 then determines a setof one or more data block identifiers 205 from the second key-valuefamily 702B that are keyed by keys that match the set of valuesdetermined from the first key-value family 702A. The determined set ofdata block identifiers 205 are then used to determine a set of datablocks 105 from the third key-value family 702C. In some embodiments, adata block identifier 205 in the second key-value family 702B issupplemented with snippet identifying information 207 identifying asnippet of the identified data block 105. An example of a two-levelsearch is “all e-mail messages sent by [X] in the past [Y] days” where[X] is the first criterion and [Y] is the second criteria.

In some embodiments, the first key-value family 702A contains key-valuepairs 110 produced by one or more adaptor(s) 103. A key in the firstkey-value family 702A may map to one or more values. Each value of a keyin the first key-value family 702A may “point” 701 to a key of a secondkey-family 702B. That is, a value of a key in the first key-value family702A may match a key in the second key-value family 702B.

In some embodiments, the second key-value family 702B contains key-valuepairs 110 produced by one or more adaptor(s) 103. Keys of the secondkey-value family 702B may match values of the first key-value family702A. Keys in the second key-value family 702B may map to one or morevalues. A value of a key in the second key-value family 702B may “point”601 to a data block 105. In some embodiments, a value of a key in thesecond key-value family 702B is a composite value comprising a datablock identifier 205 and snippet identifying information 207 identifyinga snippet of the uncompressed data block 105 identified by the datablock identifier 205.

Importer—Example Detailed Operation:

Turning now to FIG. 4, therein is shown an example operation of theimporter 109 of FIG. 1 according to one or more embodiments of theinvention. As shown, the importer 109 may receive as input a stream ofparse items 206 from the transformer 107. Each received parse item 206may contain a data block identifier 205, snippet identifying information207, and/or one or more parse tokens 106 and/or one or more transformedparse tokens 108 (not shown). As output, the importer 109 may produce astream of key-value pair items 401 from the input stream of parse items206. Each key-value pair item 401 may include a key-value familyidentifier 402 and a key-value pair 110 consisting of a key 403 and avalue 404. The importer 109 may send the stream of key-value pair items401 to the data repository 111 to be stored therein, for example, aspart of a series of database commands.

How the importer 109 forms and generates key-value pairs 110 from theinput stream of parse items 206 will depend on the expected searches tobe performed.

In some embodiments, for single-level searches specifying a searchcriterion, one key-value pair item 401 is produced by the importer 109for each input parse item 206. Referring to the exemplary single-levelsearch data model 600 of FIG. 6, the key-value pair item 401 containsthe key-value family identifier 402 of the key-value family 602A towhich the key-value pair 110 of the key-value item 401 is to be added.The key 403 of the key-value item 401 is generated from parse tokens 106and/or 108 of the input parse item 206 based on how the keys of thekey-value family 602A will be searched using the search criterion of thesingle-level search. For example, if the search criterion will be a textstring such as, for example, a person's name, an e-mail address, and IPaddress, etc., then the key 403 of each key-value item 401 may be a bytesequence representing a string formed by the importer 109 from parsetokens 106 and/or transformed parse tokens 108. The value 404 of thekey-value item 401 may be generated from the data block identifier 205and the snippet identifying information 207 of the input parse item 206to form a composite data block identifier value such as the one shown inFIG. 6.

In some embodiments, for single-level searches, multiple key-value pairitems 401 may be produced by the importer 109 for an input parse item206. In this case, the key-value family identifier 402 and the value 404of the key-value pair 110 may be the same for each of the multiplekey-value pair items 401. However, the key 403 of the key-value pair 110may be different for each of the multiple key-value pair items 401produced for the input parse item 206. Producing multiple key-value pairitems 401 for an input parse item 206 may be useful for indexing in thedata repository 111 by multiple keys 403, the same snippet of the datablock 105 identified by the data block identifier 205 of the input parseitem 206. For example, for an input parse item 206 with a parse token106 “john.smith@example.com”, the importer 109 could, for example,produce three key-value pair items 401 one with a key 403 of“john.smith”, another with a key 403 of “john smith”, and yet anotherwith a key 403 of “john.smith@example.com”. Thus, a search criterion ofany of “john.smith”, “john smith”, or “john.smith@example.com” mayproduce the same data block 105 snippet as a search result.

In some embodiments, for two level searches specifying a first searchcriterion and one or more second search criteria, two key-value pairitems 401 are produced by the importer 109 for an input parse item 206.Referring to the exemplary single-level search data model 700 of FIG. 7,for two-level searches, the importer 109 produces a first key-value pairitem 401 containing the key-value family identifier 402 of the firstkey-value family 702A and produces a second key-value pair item 401containing the key-value family identifier 402 of the second key-valuefamily 702B. The key 403 of the first key-value item 401 may begenerated from parse tokens 106 and/or 108 of the input parse item 206based on how the keys of the first key-value family 702A will besearched using the first search criterion of the two-level search. Thevalue 404 may be generated based on the key 403 and parse tokens 106and/or 108 of the input parse item 206 based on how the values of thefirst key-value family 702A will be searched using the second searchcriteria.

For example, assume the system will be used to search for “all e-mailaddresses sent by [x] within the past [y] days” where [x] is the firstsearch criterion and [y] is the second search criteria. Given an e-mailmessage with SMTP headers that specify that the message was sent from“John Smith<john.smith@example.com>” on “Thu, 23 Aug. 201018:58:04+0000”, the importer 109 may produce a first key-value pair item401 with a key 403 of “john.smith@example.com” and a value 404 of“john.smith@example.com_(—)1282589884” where the portion of the value“1282589884” is a fixed-width string representing the number of secondssince an epoch of Jan. 1, 1970 GMT that the e-mail message was sent.Formatting the date/time in this way facilitates range searches based onthe second search criteria. For example, all e-mail messages sent by“john.smith@example.com” sent in the past five days can be found bysearching for key-value pairs 110 in the first key-value family 702Awhere the key equals “john.smith@example.com” and the value is greaterthan or equal to “john.smith@example.com_<SECONDS>” where <SECONDS> is afixed-width string representing the number of seconds since the epochfive days ago from a time the search was requested or performed. Notethat the underscore character ‘_’ used in the example value 404“john.smith@example.com_(—)1282589884” is an arbitrary delimiterseparating the e-mail address from the time value and other delimitersor no delimiters could be used. For example, the value could just aseasily be “john.smith@example.com#1282589884” or“john.smith@example.com1282589884”.

The key 403 of the second key-value item 401 may be the value 404 of thefirst key-value item 401 such that the key-value pair 110 of the firstkey-value item 401 to be stored in the first key-value family 702Apoints 701 to the key-value pair of the second key-value item 401 to bestored in the second key-value family 702B. Returning to the example inthe previous paragraph, the key 403 of the second key-value item 401 forthe e-mail message may be “john.smith@example.com_(—)1282589884”. Thevalue 404 of the second key-value item 401 may be generated from thedata block identifier 205 and the snippet identifying information 207 ofthe input parse item 206 to form a composite data block identifier valuesuch as the one shown in FIG. 7. For example, the value 404 of thesecond key-value item 401 may point 601 to the data block 105 stored inthe third key-value family 702C containing the e-mail message sent byJohn Smith on Thu, 23 Aug. 2010 18:58:04 GMT.

In some embodiments, as with single-level searches, in two-levelsearches, multiple first key-value pair items 401 may be produced by theimporter 109 for an input parse item 206. In this case, the key-valuepairs 110 of each of the multiple first key-value pair items 401 may bedifferent from one another. For example, returning again to the e-mailmessage example above, three first key-value pair items 401 with threedifferent key-value pairs 110 may be generated by the importer 109 asfollows:

key=“john.smith@example.com”;value=“john.smith@example.com_(—)1282589884”

key=“john.smith”; value=“john.smith_(—)1282589884”

key=“john smith”; value=“john smith_(—)1282589884”

These three key-value pairs 110 may then be stored by the importer 109in the first key-value family 702A. Three corresponding key-value pairs110 may be stored by the importer 109 in the second key-value family702B in which each key matches a value of one of the three key-valuepairs 110 above stored in the first key-value family 702A. Note that ifJohn Smith has sent many e-mail messages, then each of the keys for JohnSmith in the first key-value family 702A (e.g.,“john.smith@example.com”, “john.smith”, and “john smith”) might eachhave multiple values, one for each message he sent.

3.0 Example Search Operation

With the above description in mind, and with reference to FIGS. 1-7,example search operations of the system of FIG. 1 in accordance withsome embodiments will now be described. In the following description, itwill be assumed for the sake of illustration that the searchfunctionality is provided by a combination of the search mechanism 113and the data repository 111. However, this is just one possibleimplementation. Other implementations where the search functionality isprovided entirely by the data repository 111 or a combination of thedata repository 111, the search mechanism 113, and one or more othersystem component(s) are also possible. All such implementations arewithin the scope of the invention.

The search mechanism 113 may be implemented in software, hardware, or acombination of software and hardware. The GUI 114 may be a stand-alonecomponent communicatively coupled to the search mechanism 113, forexample via a data network or other communication bus. Alternatively,the GUI 114 may be a component of the search mechanism 113, for exampleas part of a desktop computer application. In either case, the searchmechanism 113 may be communicatively coupled to one or more nodes 112 ofthe data repository 111, for example via a data network.

The search mechanism 113 receives as input a set of search parametersand provides as output a set of search results. The set of searchparameters may be provided to the search mechanism 113 by a data analystthrough the GUI 114, for example. The set of search results of areobtained from the data repository 111 by the search mechanism 113 basedon the input set of search parameters. In some embodiments, the set ofsearch parameters may be for one of two types of searches: (1) asingle-level search, or (2) a two-level search. Because searchfunctionality may be carried out differently depending on whether theset of search parameters are for a single-level search or a two-levelsearch, the search functionality will be described separately for eachtype of search. For the sake of simplicity, the following descriptionpresents a single-level search operation and a two-level searchoperation including example search parameters. However, it should beunderstood that single-level searches and two-level searches specifyingother search parameters are supported.

3.1 Example Single-Level Search Operation

Turning now to FIG. 8, therein is shown a flow diagram of a process 800for carrying out a single-level search in accordance with one or moreembodiments of the invention. Initially, the search mechanism 113obtains (block 801) a search criterion. Generally, the search criterionis a byte sequence that will be used by the search mechanism 113 as akey to the first key-value family 602A of the data repository 111. Thesearch criterion may be derived by the search mechanism 113 from searchparameter(s). Such derivation may include transformation,canonicalization, formatting, conversion, or encoding of the searchparameter(s). The search parameter(s) may be submitted to the searchmechanism 113 by a data analyst through the GUI 114. Alternatively, thesearch parameter(s) may be submitted to the search mechanism 113 by acomputerized agent or network client. The search criterion may, forexample, be a UTF-8 encoded character string derived from a searchparameter submitted to the search mechanism 113 by a data analystthrough a search interface of the GUI 114.

Next, the search mechanism 113 uses (block 802) the search criterion toobtain one or more values from the first key-value family 602A. Inparticular, the search mechanism 113 submits a search request to a node112 of the data repository 111. The search request is for some or all ofthe values of the key, if there is one, of the first key-value family602A that matches (equals) the search criterion. Recall that all keys ofa key-value family may be unique at least within that key-value family.Further, recall that a key of a first key-value family may have morethan one value. Assuming a key matching the search criterion exists inthe first key-value family 602A, then the search request is expected toobtain one or more values to which that key is mapped in the firstkey-value family 602A. In some embodiments, at least one of the one ormore values comprises a data block identifier 205. In some embodiments,at least one of the one or more values comprises snippet identifyinginformation 207 identifying a snippet of an uncompressed data block 105.

In some embodiments, the search request specifies a cap on the number ofvalues to obtain. In particular, a key matching the search criterion maymap in the first key-value family 602A to thousands, millions, or evenbillions of values. Thus, it may be impractical or inefficient for thesearch mechanism 113 to obtain all values for the key in a single searchrequest. Instead, the search request specifies a number of values forthe key to obtain. This number may correspond roughly to the number ofsearch results that the GUI 114 will display at any one time, forexample.

In some embodiments, values for the key that matches the searchcriterion are obtained by the search mechanism 113 in one or morebatches. This is done to avoid having to retrieve and materialize all ora large number of values for the key (which could number into themillions or even billions of values) in a volatile memory of the searchmechanism 113. This batching technique can be used where the values forthe key are stored in the data repository 111 in a sorted order suchthat ranges or slices of ordered values can be iteratively retrievedfrom the data repository 111. This batching technique operates generallyas follows:

1. A first search request is submitted to a node 112 of the datarepository 111 requesting the first N number of values of the key of thefirst-key value family 602A matching the search criterion. This returnsa first set of up to N values in a sorted order.

2. If the first set of values contains N values, then there may be morevalues to obtain. To do so, a second search request is submitted butthis time requesting a next number of values of the key that are greaterthan the last value in the first set of values.

3. Further search requests may be submitted to obtain successive batchesof values, each requesting some number of values of the key that aregreater than the last value in the immediately previously obtained batchof values.

This batching technique may be used, for example, as the data analystrequests successive pages of search results through the GUI 114.

Next, the search mechanism 113 uses (block 803) the one or more valuesobtained from the first key-value family 602A to obtain one or more datablocks 105 from the second key-value family 602B. In some embodiments,the search mechanism 113 submits a search request to a node 112 of thedata repository 111 for each value of the one or more values obtainedfrom the first key-value family 602A. Each such search request specifiesa data block identifier 205 as a key to the second key-value family602A. The data block identifier 205 is obtained or derived from thecorresponding value of the one or more values obtained from the firstkey-value family 602A for which the search request is being submitted.As a result, the search mechanism 113 obtains one or more data blocks105 from the second key-value family 602B, one for each of the one ormore values obtained from the first key-value family 602A.

A data block 105 obtained from the second key-value family 602B may becompressed or uncompressed. If compressed, the search mechanism 113uncompresses (block 804) the data block 105 to produce a correspondinguncompressed data block 105. As a result, the search mechanism 113obtains and/or produces one or more uncompressed data blocks 105corresponding to the one or more data blocks 105 obtained from thesecond key-value family 602B.

Next, the search mechanism 113 uses (block 805) the one or more valuesobtained from the first key-value family 602A to identify one or moreportions of the one or more uncompressed data blocks 105. As mentioned,a value from the first key-value family 602A may be encoded with snippetidentifying information 207 identifying a snippet (byte sequentialportion) of an uncompressed data block 105. The snippet may, forexample, correspond to a logical data entity 201 (e.g., an e-mailmessage, a log entry, a call data record, a netflow, etc.) of theuncompressed data block 105.

Next, the search mechanism 113 returns (block 806) the one or moreidentified portions of the one or more uncompressed data blocks assearch results. For example, the one or more identified portions may bepresented by the search mechanism 113 in the GUI 114. The search resultscontaining the one or more identified portions may be returned by thesearch mechanism 113 in any suitable data format (e.g., XML, HTML,etc.).

3.2 Example Two-Level Search

Turning now to FIG. 9, therein is shown a flow diagram of a process 900for carrying out a two-level search in accordance with one or moreembodiments of the invention. Initially, the search mechanism 113obtains (block 901) a first search criterion and one or more secondsearch criteria. Generally, the first search criterion is a bytesequence that will be used by the search mechanism 113 as a key to thefirst key-value family 702A of the data repository 111. Each of thesecond search criteria may also be a byte sequence and is used by thesearch mechanism 113 as a predicate on the values of that key in thefirst key-value family 702A.

The first search criterion may be derived by the search mechanism 113from search parameter(s). Such derivation may include transformation,canonicalization, formatting, conversion, or encoding of searchparameter(s). The search parameter(s) may be submitted to the searchmechanism 113 by a data analyst through the GUI 114. Alternatively, thesearch parameter(s) may be submitted to the search mechanism 113 by acomputerized agent or network client. The first search criterion may,for example, be a UTF-8 encoded character string derived from a searchparameter submitted to the search mechanism 113 by a data analystthrough a search interface of the GUI 114.

The second search criteria may also be derived by the search mechanism113 from search parameter(s). The derivation may also includetransformation, canonicalization, formatting, conversion, or encoding ofsearch parameter(s). In addition, a search criterion of the one or moresecond search criteria may be derived in part based on the first searchcriterion and search parameter(s). Specifically, the search mechanism113 may derive a second search criterion based on how the values of thefirst key-value family 702A were populated by adaptor(s) 103. Forexample, assume a two-level search of “all network access from networkaddress [X] in the past [Y] days”. In this case, an adaptor(s) 103 mayhave populated the keys of the first key-value family 702A with networkaddresses and populated the first key-family 702B with values of theform “<network address>_<milliseconds since epoch>” where <networkaddress> is the key for this value and <milliseconds since epoch> is afixed-width string representing the date/time the associated networkaddress made a network access. In this case, the search mechanism 113may generate a second search criterion by appending a value derived froma search parameter for [Y] to the first search criterion separated by anunderscore character ‘_’. The value derived from the search parameter[Y] might, for example, be a fixed-width string representing a date/timein the past specified by the search parameter.

As mentioned, the search mechanism 113 uses (block 902) the secondsearch criteria as a predicate on the values of the key in the firstkey-value family 702A that matches (equals) the first search criterionto obtain one or more first values of that key. Recall that the valuesof a key in the first key-value family 702A may be stored in a sortedorder in the data repository 111. Returning the example in the previousparagraph, the values of a key might be stored in increasing order ofdate/time as determined by the fixed-width string portion of the valuerepresenting a time in milliseconds since an epoch. The search mechanism113 may use the second search criteria to select individual value(s),slice(s) of values, or a combination of individual value(s) and slice(s)of values. Individual values may be selected using an equalityoperation. Slices of values may be selected using a greater than,greater than or equal to, less then, or less than or equal to operation.The number of second search criteria that the search mechanism 113 useswill depend on the particulars of the two-level search. For example, theexample two-level search in the previous paragraph, the search mechanismmay use only one second search criterion in conjunction with a greaterthan operation or a greater than or equal to operation to determine thevalues of a key corresponding network accesses from a given networkaddress in the past [Y] days. As another example, the search mechanism113 might use two second search criterion to specify a bounded timerange in the past for a two-level search like “all network access fromnetwork address [X] between date/time: [Y] and date/time: [Z]”.

When using (block 902) the first search criterion and the one or moresecond search criteria to obtain one or more first values from the firstkey-value family 702A, the search mechanism 113 may employ the batchingstrategy described above with respect to the single-level search.

Assuming a key matching the first search criterion exists in the firstkey-value family 702A, then the search mechanism 113 obtains (block902), from the first-key value family 702A, one or more first values ofthat key that satisfy the one or more second criteria. In someembodiments, at least one of the one or more first values comprises akey to the second key-value family 702B.

Next, the search mechanism 113 uses (block 903) the one or more firstvalues obtained from the first key-value family 702A to obtain one ormore second values from the second key-value family 702B. In someembodiments, the search mechanism 113 submits a search request to a node112 of the data repository 111 for each value of the one or more firstvalues obtained from the first key-value family 702A. Each such searchrequest specifies a value of the one or more first values as a key tothe second key-value family 702A. As a result, the search mechanism 113obtains one or more second values from the second key-value family 702B,one for each of the one or more first values obtained from the firstkey-value family 702A.

Next, the search mechanism 113 uses (block 904) the one or more secondvalues obtained from the second key-value family 702B to obtain one ormore data blocks 105 from the third key-value family 70CB. In someembodiments, the search mechanism 113 submits a search request to a node112 of the data repository 111 for each value of the one or more secondvalues obtained from the second key-value family 702B. Each such searchrequest specifies a data block identifier 205 as a key to the thirdkey-value family 702C. The data block identifier 205 is obtained orderived from the corresponding value of the one or more second valuesobtained from the second key-value family 702B for which the searchrequest is being submitted. As a result, the search mechanism 113obtains one or more data blocks 105 from the third key-value family702C, one for each of the one or more values obtained from the secondkey-value family 702B.

A data block 105 obtained from the third key-value family 702C may becompressed or uncompressed. If compressed, the search mechanism 113uncompresses the data block 105 to produce a corresponding uncompresseddata block 105. As a result, the search mechanism 113 obtains and/orproduces one or more uncompressed data blocks 105 corresponding to theone or more data blocks 105 obtained from the third key-value family702C.

Next, the search mechanism 113 uses the one or more second valuesobtained from the second key-value family 702B to identify one or moreportions of the one or more uncompressed data blocks 105. As mentioned,a value from the second key-value family 7B02A may be encoded withsnippet identifying information 207 identifying a snippet (bytesequential portion) of an uncompressed data block 105.

Next, the search mechanism 113 returns (block 905) the one or moreidentified portions of the one or more uncompressed data blocks 105 assearch results.

While the above description and accompanying flowcharts describe ordepict steps being performed in a certain order. It will be apparentthat steps may be performed in a different order or concurrently withoutdeparting from the spirit and scope of the invention. For example, ifthe batching technique is used, then one or more of steps 803-806 may beperformed on an already obtained batch of values from the firstkey-value family 602A concurrently while step 802 is performed to obtainthe next batch of values. Similarly, one or more of steps 903-905 may beperformed concurrently with step 902. As another example, requests toobtain data blocks 105 from the data repository 111 as in steps 803 and904 may be made concurrently. Requests of step 903 to obtain values fromthe second key-value family 702B may be made concurrently. Decompressingmultiple compressed values as in step 804 may also be performedconcurrently.

4.0 Example Implementing Mechanism

According to one embodiment, the techniques described herein areimplemented by one or more special-purpose computing devices. Thespecial-purpose computing devices may be hard-wired to perform thetechniques, or may include digital electronic devices such as one ormore application-specific integrated circuits (ASICs) or fieldprogrammable gate arrays (FPGAs) that are persistently programmed toperform the techniques, or may include one or more general purposehardware processors programmed to perform the techniques pursuant toprogram instructions in firmware, memory, other storage, or acombination. Such special-purpose computing devices may also combinecustom hard-wired logic, ASICs, or FPGAs with custom programming toaccomplish the techniques. The special-purpose computing devices may bedesktop computer systems, portable computer systems, handheld devices,networking devices or any other device that incorporates hard-wiredand/or program logic to implement the techniques.

For example, FIG. 10 is a block diagram that illustrates a computersystem 1000 upon which an embodiment may be implemented. Computer system1000 includes a bus 1002 or other communication mechanism forcommunicating information, and a hardware processor 1004 coupled withbus 1002 for processing information. Hardware processor 1004 may be, forexample, a general purpose microprocessor.

Computer system 1000 also includes a main memory 1006, such as a randomaccess memory (RAM) or other dynamic storage device, coupled to bus 1002for storing information and instructions to be executed by processor1004. Main memory 1006 also may be used for storing temporary variablesor other intermediate information during execution of instructions to beexecuted by processor 1004. Such instructions, when stored in storagemedia accessible to processor 1004, render computer system 1000 into aspecial-purpose machine that is customized to perform the operationsspecified in the instructions.

Computer system 1000 further includes a read only memory (ROM) 1008 orother static storage device coupled to bus 1002 for storing staticinformation and instructions for processor 1004. A storage device 1010,such as a magnetic disk or optical disk, is provided and coupled to bus1002 for storing information and instructions.

Computer system 1000 may be coupled via bus 1002 to a display 1012, suchas a cathode ray tube (CRT), for displaying information to a computeruser. An input device 1014, including alphanumeric and other keys, iscoupled to bus 1002 for communicating information and command selectionsto processor 1004. Another type of user input device is cursor control1016, such as a mouse, a trackball, or cursor direction keys forcommunicating direction information and command selections to processor1004 and for controlling cursor movement on display 1012. This inputdevice typically has two degrees of freedom in two axes, a first axis(e.g., x) and a second axis (e.g., y), that allows the device to specifypositions in a plane.

Computer system 1000 may implement the techniques described herein usingcustomized hard-wired logic, one or more ASICs or FPGAs, firmware and/orprogram logic which in combination with the computer system causes orprograms computer system 1000 to be a special-purpose machine. Accordingto one embodiment, the techniques herein are performed by computersystem 1000 in response to processor 1004 executing one or moresequences of one or more instructions contained in main memory 1006.Such instructions may be read into main memory 1006 from another storagemedium, such as storage device 1010. Execution of the sequences ofinstructions contained in main memory 1006 causes processor 1004 toperform the process steps described herein. In alternative embodiments,hard-wired circuitry may be used in place of or in combination withsoftware instructions.

The term “non-transitory media” as used herein refers to any media thatstore data and/or instructions that cause a machine to operation in aspecific fashion. Such non-transitory media may comprise non-volatilemedia and/or volatile media. Non-volatile media includes, for example,optical or magnetic disks, such as storage device 1010. Volatile mediaincludes dynamic memory, such as main memory 1006. Common forms ofnon-transitory media include, for example, a floppy disk, a flexibledisk, hard disk, solid state drive, magnetic tape, or any other magneticdata storage medium, a CD-ROM, any other optical data storage medium,any physical medium with patterns of holes, a RAM, a PROM, and EPROM, aFLASH-EPROM, NVRAM, any other memory chip or cartridge.

Non-transitory media is distinct from but may be used in conjunctionwith transmission media. Transmission media participates in transferringinformation between non-transitory media. For example, transmissionmedia includes coaxial cables, copper wire and fiber optics, includingthe wires that comprise bus 1002. Transmission media can also take theform of acoustic or light waves, such as those generated duringradio-wave and infra-red data communications.

Various forms of media may be involved in carrying one or more sequencesof one or more instructions to processor 1004 for execution. Forexample, the instructions may initially be carried on a magnetic disk orsolid state drive of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over atelephone line using a modem. A modem local to computer system 1000 canreceive the data on the telephone line and use an infra-red transmitterto convert the data to an infra-red signal. An infra-red detector canreceive the data carried in the infra-red signal and appropriatecircuitry can place the data on bus 1002. Bus 1002 carries the data tomain memory 1006, from which processor 1004 retrieves and executes theinstructions. The instructions received by main memory 1006 mayoptionally be stored on storage device 1010 either before or afterexecution by processor 1004.

Computer system 1000 also includes a communication interface 1018coupled to bus 1002. Communication interface 1018 provides a two-waydata communication coupling to a network link 1020 that is connected toa local network 1022. For example, communication interface 1018 may bean integrated services digital network (ISDN) card, cable modem,satellite modem, or a modem to provide a data communication connectionto a corresponding type of telephone line. As another example,communication interface 1018 may be a local area network (LAN) card toprovide a data communication connection to a compatible LAN. Wirelesslinks may also be implemented. In any such implementation, communicationinterface 1018 sends and receives electrical, electromagnetic or opticalsignals that carry digital data streams representing various types ofinformation.

Network link 1020 typically provides data communication through one ormore networks to other data devices. For example, network link 1020 mayprovide a connection through local network 1022 to a host computer 1024or to data equipment operated by an Internet Service Provider (ISP)1026. ISP 1026 in turn provides data communication services through theworld wide packet data communication network now commonly referred to asthe “Internet” 1028. Local network 1022 and Internet 1028 both useelectrical, electromagnetic or optical signals that carry digital datastreams. The signals through the various networks and the signals onnetwork link 1020 and through communication interface 1018, which carrythe digital data to and from computer system 1000, are example forms oftransmission media.

Computer system 1000 can send messages and receive data, includingprogram code, through the network(s), network link 1020 andcommunication interface 1018. In the Internet example, a server 1030might transmit a requested code for an application program throughInternet 1028, ISP 1026, local network 1022 and communication interface1018.

The received code may be executed by processor 1004 as it is received,and/or stored in storage device 1010, or other non-volatile storage forlater execution.

In the foregoing specification, embodiments have been described withreference to numerous specific details that may vary from implementationto implementation. Thus, the sole and exclusive indicator of what is theinvention, and is intended by the applicants to be the invention, is theset of claims that issue from this application, in the specific form inwhich such claims issue, including any subsequent correction. Anydefinitions expressly set forth herein for terms contained in suchclaims shall govern the meaning of such terms as used in the claims.Hence, no limitation, element, property, feature, advantage or attributethat is not expressly recited in a claim should limit the scope of suchclaim in any way. The specification and drawings are, accordingly, to beregarded in an illustrative rather than a restrictive sense.

What is claimed is:
 1. A method comprising: using a computer that isconfigured with an improved search mechanism, receiving a searchparameter; using the computer and the improved search mechanism,deriving a search criterion from the search parameter and using thesearch criterion to obtain one or more first values from a first-keyvalue family of a key-value data repository stored in a data storagedevice that is coupled to the computer; using the computer and theimproved search mechanism, using the one or more first values to obtainone or more compressed values from a second key-value family of thekey-value data repository; using the computer and the improved searchmechanism, uncompressing the one or more compressed values to produceone or more uncompressed values; using the computer and the improvedsearch mechanism, using the one or more first values to identify one ormore portions of the one or more uncompressed values; using the computerand the improved search mechanism, returning the one or more portions ofthe one or more uncompressed values as search results.
 2. The method ofclaim 1, wherein the first key-value family comprises a first set ofunique keys, each key in the first set of unique keys mapping to one ormore values; wherein the second key-value family comprises a second setof unique keys, each key in the second set of unique keys mapping to atleast one compressed value.
 3. The method of claim 1, wherein at leastone of the one or more first values comprises an identifier of acompressed value of the one or more compressed values.
 4. The method ofclaim 1, wherein at least one of the one or more first values comprisesa key of the second key-value family.
 5. The method of claim 1, whereinat least one of the one or more first values comprises informationidentifying a byte sequential portion of one of the one or moreuncompressed values.
 6. The method of claim 1, wherein at least one ofone or more portions is a byte sequential portion of an uncompressedvalue of the one or more uncompressed values.
 7. The method of claim 1,wherein each key of the first key-value family is unique at leastamongst all keys of the first key-value family.
 8. The method of claim1, wherein using the search criterion to obtain the one or more firstvalues includes selecting a key from the first key-value family thatequals the search criterion.
 9. The method of claim 1 wherein thekey-value data repository comprises a cluster of a plurality ofcomputing nodes; wherein at least one key of the first key-value familyis mastered by at least one node of the plurality nodes and at least oneother key of the first key-value family is mastered by at least oneother node of the plurality of nodes; wherein each and every node of thecluster of nodes is configured to obtain values for any key of the firstkey-value family.
 10. A method comprising: using a computer that isconfigured with an improved search mechanism, receiving a searchparameter and determining a first search criterion and one or moresecond search criteria based upon the search parameter; using thecomputer and the improved search mechanism, using the first searchcriterion and the second search criteria to obtain one or more firstvalues from a first-key value family of a key-value data repository of adata storage device that is coupled to the computer; using the computerand the improved search mechanism, using the one or more first values toobtain one or more second values from a second key-value family of thekey-value data repository; using the computer and the improved searchmechanism, using the one or more second values to obtain one or morecompressed values from a third key-value family of the key-value datarepository; using the computer and the improved search mechanism,returning one or more uncompressed portions of the one or morecompressed values as search results.
 11. The method of claim 10, furthercomprising, using the computer and the improved search mechanism,uncompressing the one or more compressed values to produce one or moreuncompressed values, and using the one or more second values to identifythe one or more uncompressed portions from the one or more uncompressedvalues.
 12. The method of claim 11, wherein at least one of the one ormore second values comprises information identifying a byte sequentialportion of one of the one or more uncompressed values.
 13. The method ofclaim 11, wherein at least one of the one or more portions is a bytesequential portion of an uncompressed value of the one or moreuncompressed values.
 14. The method of claim 10, wherein using the firstsearch criterion and the second search criteria to obtain the one ormore first values comprises selecting all values of a key of the firstkey-value family that equals the first search criterion where theselected values satisfy the second search criteria.
 15. The method ofclaim 10, wherein the first key-value family comprises a first set ofunique keys and a set of values to which the first set of unique keysare mapped; wherein the second key-value family comprises a second setof unique keys and a set of values to which the second set of uniquekeys are mapped; wherein the third key-value family comprises a thirdset of unique keys and a set of values to which the third set of uniquekeys are mapped; wherein at least one value of each key in the first setof unique keys matches a key of the second set of unique keys; whereinat least one value of each key in the second set of unique keys matchesa key of the third set of unique keys.
 16. The method of claim 10,wherein at least one of the one or more second values comprises anidentifier of a compressed value of the one or more compressed values.17. The method of claim 10, wherein each key of the first key-valuefamily is unique at least amongst all keys of the first key-valuefamily.
 18. The method of claim 10 wherein the key-value data repositorycomprises a cluster of a plurality of computing nodes; wherein at leastone key of the first key-value family is mastered by at least one nodeof the plurality nodes and at least one other key of the first key-valuefamily is mastered by at least one other node of the plurality of nodes;wherein each and every node of the cluster of nodes is configured toobtain values for any key of the first key-value family.
 19. A dataprocessing system comprising: a computer comprising one or moreprocessors; a key-value data repository in a data storage device that iscoupled to the computer and comprising a first key-value family and asecond key-value family; an improved search mechanism in the computerand configured to: receive a search parameter and determine a searchcriterion based upon the search parameter; use the search criterion toobtain one or more first values from the first-key value family; use theone or more first values to obtain one or more compressed values fromthe second key-value family; uncompress the one or more compressedvalues to produce one or more uncompressed values; use the one or morefirst values to identify one or more portions of the one or moreuncompressed values; return the one or more portions of the one or moreuncompressed values as search results.
 20. The system of claim 19wherein the first key-value family comprises a first set of unique keys,each key in the first set of unique keys mapping to one or more values;wherein the second key-value family comprises a second set of uniquekeys, each key in the second set of unique keys mapping to at least onecompressed value.
 21. The system of claim 19, wherein at least one ofthe one or more first values comprises a key of the second key-valuefamily.
 22. The system of claim 19, wherein at least one of the one ormore first values comprises information identifying a byte sequentialportion of one of the one or more uncompressed values.
 23. The system ofclaim 19, wherein the search mechanism is configured to use the searchcriterion to obtain the one or more first values by selecting a key fromthe first key-value family that equals the search criterion.
 24. Thesystem of claim 19 wherein the key-value data repository comprises acluster of a plurality of computing nodes; wherein at least one key ofthe first key-value family is mastered by at least one node of theplurality nodes and at least one other key of the first key-value familyis mastered by at least one other node of the plurality of nodes;wherein each and every node of the cluster of nodes is configured toobtain values for any key of the first key-value family.
 25. A datasystem comprising: a computer comprising one or more processors; akey-value data repository in a data storage device that is coupled tothe computer and comprising a first key-value family, a second key-valuefamily, and a third key-value family; an improved search mechanism inthe computer and configured to: receive a search parameter and determinea first search criterion and one or more second search criteria basedupon the search parameter; use the first search criterion and the secondsearch criteria to obtain one or more first values from the first-keyvalue family; use the one or more first values to obtain one or moresecond values from the second key-value family; use the one or moresecond values to obtain one or more compressed values from the thirdkey-value family; return one or more uncompressed portions of the one ormore compressed values as search results.
 26. The system of claim 25,wherein the search mechanism is further configured to: uncompress theone or more compressed values to produce one or more uncompressedvalues; use the one or more second values to identify the one or moreuncompressed portions from the one or more uncompressed values.
 27. Thesystem of claim 26, wherein at least one of the one or more secondvalues comprises information identifying a byte sequential portion ofone of the one or more uncompressed values.
 28. The system of claim 25,wherein the search mechanism is further configured to generate at leastone of the second criteria using the first criterion and a searchparameter obtained from a user.
 29. The system of claim 25, wherein thesearch mechanism is configured to use the first search criterion and thesecond search criteria to obtain the one or more first values byselecting values of a key of the first key-value family that equals thefirst search criterion where the selected values satisfy the secondsearch criteria.
 30. The system of claim 25 wherein the first key-valuefamily comprises a first set of unique keys and a set of values to whichthe first set of unique keys are mapped; wherein the second key-valuefamily comprises a second set of unique keys and a set of values towhich the second set of unique keys are mapped; wherein the thirdkey-value family comprises a third set of unique keys and a set ofvalues to which the third set of unique keys are mapped; wherein atleast one value of each key in the first set of unique keys matches akey of the second set of unique keys; wherein at least one value of eachkey in the second set of unique keys matches a key of the third set ofunique keys.
 31. The system of claim 25 wherein the key-value datarepository comprises a cluster of a plurality of computing nodes;wherein at least one key of the first key-value family is mastered by atleast one node of the plurality nodes and at least one other key of thefirst key-value family is mastered by at least one other node of theplurality of nodes; wherein each and every node of the cluster of nodesis configured to obtain values for any key of the first key-valuefamily.